摘要
从地震影响系数曲线的特征周期Tg出发,提出了分别取1/5Tg和1/Tg作为时域计算瑞利(Rayleigh)阻尼的两个目标频率。通过3种不同厚度的单一土层和1种多层土层模型在3条不同地震动作用下的计算,比较了基于Annie方法和本文方法确定Rayleigh阻尼的时域解,以及基于等效线性化的频域解,结果表明:两种Rayleigh阻尼形式的地表加速度峰值误差都在10%以内,地表加速度反应谱基本一致,但本文方法对土层厚度和输入的地震动不太敏感,即误差随着土层厚度及输入地震动的不同离散性很小,且应用更为简便,无需求土层的自振频率,只需要根据场地类别获得场地特征周期,就可确定Rayleigh阻尼值。
Based on the characteristic period of the seismic influence coefficient curve, a new method to calculate Rayleigh damping is put forward that taking 1/5Tg and 1/Tg as the two target frequencies respectively. Time domain results based on the method put forward by Annie and the new method in this paper, and together with the frequency domain results based on equivalent linear method are compared by three single homogeneous soils with different thicknesses and a multilayered soil under three different ground motions. The results show that:the errors of the ground peak acceleration of the two forms of Rayleigh damping are within 10%;and the ground acceleration response spectra are consistent, but the method in this paper is not sensitive to soil thickness and input ground motions, that is, the error dispersions are small with different soil thicknesses and input ground motions. What’s more, the method in this paper is simpler and more convenient in application. For the method in this paper, the Rayleigh damping values can be determined by the characteristic period obtained from local site category, without the need of solving natural frequencies of soil.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第S2期35-40,共6页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51278323)
